Near the warehouse, also on a high plinth, is the upper town or acropolis which spans 128 by 61 meters and has extensive drainage systems.
Ancient Indus civilization sanitation related facilities.
The "great bath" is without doubt the earliest public water tank in the ancient world. The tank itself measures approximately 12 meters north-south and 7 meters wide, with a maximum depth of 2.4 meters.
The proximity of the seat of power to the warehouse may have ensured that the ruler and his entourage could inspect stocks easily. An ivory workshop in the acropolis suggests that elephants may have been domesticated to produce the raw material.
An elaborate sanitary and drainage system, a hallmark of ancient Indus cities, is in evidence everywhere at Lothal.
Private wells were rebuilt over many generations to serve the needs of a large household or neighborhood. This well in DK G area at Mohenjo-daro stands like a chimney because all of the surrounding earth has been removed by excavation.
Almost every house unit at Mohenjo-daro was equipped with a private bathing area with drains to take the dirty water out into a larger drain that emptied into a sewage drain.
The most unique aspect of planning during the Indus Valley civilization was the system of underground drainage. The main sewer, 1.5 meters deep and 91 cm across, connected to many north-south and east-west sewers.
A large public well and public bathing platforms were found in the southern part of Mound AB at Harappa. These public bathing areas may also have been used for washing clothes as is common in many traditional cities in Pakistan and India today.
The floor slopes down to the southwest corner where a small outlet (top right) leads to a brick drain, which takes the water to the edge of the mound.